Gear pump for oil burners



Jan. 27, 1931. F. FISCHER ET AL 1,790,371 GEAR IfUMP FOR OIL BURNERS Original Filed July 14. 1927 5 Sheets-Sheet 1 O in 1 I 1 i i 1 l I l I I l I Fig. 1

o H e: 52 :1 3 r- 3 5 3 b INVENTORS I Jan. 27, 1931.

GEAR PUMP FOR OIL BURNERS Original Filed July 14. 1927 F. FISCHER ET AL Qj/ V 3 Shuts-Sheet 2 Jan. 27,1931. F. FISCHER ET AL 1,790,371

GEAR PUMP FOR OIL BURNERS Original Filed July 14. 1927 s Sheets-Sheet a INVENTORS Patented Jan. 27, 1931 UNITED STATES, FATE FRANK FISCHER, or LARCHMON'I, AND GUDMUND sivnncrsnrzr, or BROOKLYN, New

i GEAR PUMP FOR OIL BURNERS Application filed 'July 14, 1927, SeriaLNc. 205,771. Renewed November 29, 1930..

i This invention relates to multiple pumps of the geartype similar to the'co-mbinatlon described in "our co-pending application, Se-

rial No. 177,070 and pertains particularly to "I an arrangement; whereby the general pering.

formance of the unit as a Whole is further subdivided into elementary duties more readily controlled by :a plurality of cooperating pumps compactly housed in a sectional cas- The casing is built of alternate discsections and housing-sections,thehousing sections being opcn'on both sides, and the disc-sections abutting and closing the sides of the housing-sections. r

In order to obtain a uniform fire it is essential that thepump delivering oil to the atomizing means be free of all variable influences. For this reason a separate feedpump is provided to receive its supply from a uniform level in shallow sump under approximately atmospheric pressure, and to deliver the oil directly to the atomizing means. 'With this arrangement slight air leakages and temporarystoppages in the main supply line, as well as variations of oil levelin. the

storage tank, cannot affect the fire.

One object of our invention, therefore, is to provide a separate pump, independent of the main supply-pump, for feeding oil uniformly to the burne V Another object is to provide easily. in-

spected oil passages by casting open channels in the casing sections; 7

Another object is to simplify and cheapen the construction of the unit. r

These. and other objects are attained by the combination of parts illustrated'in the accompanying drawings in which Fig. I is a longitudinal. vertical section of our pumping unit.

Fig. II isa transverse section taken on line 2-2 of Fig. I,sshowing the supply-pump gears and the housing-section enclosing them.

Fig. III is a transverse section taken on line 33 of Fig. I, showing the feed-pumpgears in relation to the channeled suction and discharge passages in the adjacent disc-section.

H of Fig. I, showing the air-pump im pellers.

Fig. V is a transverse section taken on line 55 of Fig. I, showing the return-pump gears. I Y

Fig. VI is a top View of the sump showing the location of the various inlet and outlet connections thereto taken on line 66 of Fig. I. Y

Similar numbers refer to similar partsthroughout the several figures in, which 1, 2, 3, 4, 5, 6, 7 8, and9 represent sections of. thecasing, the even numbers being housingsections, and the odd numbers disc-sections closing the open sides of the housing-sections.

1 is theout-board housing-section of the casing having formed therein cavity 10 con- N'r LOFFVIICE' a GRANT OIL BURNER CORPORATION or DELASKTARE, or New taining the oil-strainer 11 carried by the plug 12 as indicated. 13 is a pipe nippleconnecting with thestrainer cavity 10at its upper end, andwith the main oil supply pipe, not shown, at the lower end.

14 is a hole through which oil passes from the strainer to the inlet of the supply-pump, which consists of gears 15 and 16 mounted on shafts 17. and 18 respectively in housingsection 2. Housing-section 2 contains slot 19 and channel 20 for. conveying the discharged oil from the supply-pump gears 15 and 16 to the discharge opening 21. Y Disc-section 8 serves to close one side of slot 19, channel 20 and opening 21, as well as the abutting sides of housing-sections 2 and 4:.

Gears 22 and 23 mounted on shafts 17 and 18 respectively constitute the rotating ele:

' channel 2 1 and drilled passage 25 connecting with suction pipe 26. Also formed in discsection 5 is discharge channel 27 and drilled hole 28 connecting with throttling nipple 29. 30 is a hole connecting with hole 28 for by passing some of the oil from the feed-pump discharge to the needle valve 31. Passage 82 in disc-section 5, registers with passage 33 in housing-section 6, and connects the outlet side of needle-valve 31 with annular feed channel 34 formed around air-pipe housing section 6.

Needle-valve 31 is controlled by slotted end of needle36 which is threaded at 37 in discsection 5, after passing through stuffingbox 38.

39 and 40 are a pair of two-teeth gears or impellers of the Roots blower type mounted on shafts 17 and 18 respectivelyso as to entrain air through air-pipe 35 and discharge it through. passage 41, connecting pipe 42 and nozzle 43 into the furnace. The furnace is not shown in the drawings.

Return-pump gears 44 and 45 are mounted on shafts 17 and 18 respectively in housing sections 8 between the abutting disc-sections 7 and 9. The latter has formed therein suction passage 46 connecting with suction nipple 47. Disc-section 7 contains discharge passage 48 connecting through discharge nipple 49 with the return pipe to the oil storage tank not shown in the drawings.

Gears 15, 22, 44, and impeller 39 are all mounted on shaft 17 while the intermeshing gears 16, 23, 45 and impeller 40 are mounted on drive shaft 18. Both shafts are rotatably supported in bearings formed in disc-sections 3, 5, and 7 while drive shaft 18 is steadied by an additional bearing formed in disc-section 9. A chamber 50 is formed in the driveend disc-section 9 where shaft 18 extends through to receive one end of the flexible coupling 51. Mounted on shaft 18 in chamber 50 is oil-throwing collar 52 for deflecting into chamber 50 any oil which might otherwise leak out along shaft 18. Drain passage 53 conveys any such oil through nipple 54 into the sump 55 formed in base 56.

Bolts 57 hold the several disc and housing sections together.

Base 56 supports the pumping unit and driving motor 58the pump being fastened to the base by means of nuts 59 around suction and discharge nipples 13 and 49 extending through the base.

Holes 60 admit air to the upper part of sump 56 above the level of the oil indicated by line 61. Sump 56 is divided at one end by partition 62, into communicating compartments 63 and 64. Opening 21 and nipple 29 discharge into compartment 63 and suction'pipe 26 and air-pipe 35 draw oil and air from compartment 64. (See Fig. VI).

The operation of our pumping unit is as follows The supply-pump gears 15 and 16 entrain oil from the main supply pipe and storage tank (not shown in the drawings) through the connecting pipe nipple 13, cavity 10, oils trainer 11, and hole 14 leading to the lower face of said gears. These gears, rotating in the direction indicated in Fig. II carry the oil between the gear-teeth and the adjacent surfaces of housing-section 2 and abutting disc-sections 1 and 3, and discharge it through slot 19, channel 20 and opening 21 into compartment 63 of the sump. The whole of the sump is thereby filled to level 61, which coincides with the lower end of suction nipple 47.

Surplus oil rising above level 61 is entrained through suction-nipple 47, and passage 46, to the spaces between the teeth of return-pump gears 44 and 45 and the adjacent surfaces of housing-section 8 and abutting disc-sections 7 and 9, and carried between said teeth and discharged through passage 48, discharge nipple 49, and return pipe back to the storage tank. In this manner a circulation of oil, and a constant'level in the sump, are maintained, from which the feed-pump gears 22 and 23 draw their supply through the connecting suction channel 24, passage 25, and suction pipe 26.

Part of the discharge from feed-pump gears 22 and 23 is conveyed back to the sump through channel 27, hole 28, and throttling nipple 29. The back-pressure produced by throttling nipple 29 causes some of the oil to by-pass through hole 30, needle-valve 31, passages 32 and 33, to feed channel 34 in housing-section 6. The amount of oil so bypassed is obviously controlled by turning needle 36.

The oil overflowing the upper end of air pipe 35 is caught by the incoming air and carried into the air-pump housing-section 6 under the suction influence of rotating impellers 39 and 40. Said impellers carry the air and oil in the cavity formed between the faces of the impellers and the confining surfaces of housing-section 6 and disc-sections 5 and 7, and discharge it through passage 41, pipe 42 and nozzle 43 into the furnace.

It will thus be apparent that the flow of oil to the furnace is independent of influences affecting the continuity of flow from the sup ply-pump, so long as the oil in the sump is maintained deep enough to submerge the lower end of suction pipe 26. This safeguards against leakage of air into the main suction line through certain types of siphonbreakers, variations of oil supply level, temporary stoppages, and many other influences causing fluctuations of the oil supply from the storage-tank.

The faces of return-pump gears 44 and 45 are made wider than those of supply-pump gears 15 and 16 in order to safeguard against any excessive accumulation of oil in the sump.

We are aware that prior to our invention individual gear-pumps and blowers of the types shown have been used extensively, and

we do not claim the gear pump construction in detail but the combination of housings and rotating elements as follows 1. In a pump of the class described, a cylindrical sectional casing consisting of alternately disposed housing-sections and discdisc-sections being located parallel and close to the sides of the gears, and the housing sections closely surrounding the faces of the gears and abutting the discsections on both sides so as to completely enclose the gears, the sections having suction and discharge channels formed in the faces thereof communicatingwith the gears and leading away therefrom in planes perpendicular to the axes of the gears, one side of each channel being closed by the adjoining section.

3. In a pumping device for oil-burners, the combination of a sump, means for maintaining a constant level of oil in the sump, a pump casing, air-pumping impellers in the casing, separate air inlet and outlet conduits communicating respectively with the suction and discharge sides of the impellers, a pair of oil feed-pump gears in the casing, an oil inlet conduit communicating with the suction side of the feed-pump gears and with the lower part of the sump for supplying oil under a uniform suction head to the gears, an oil outlet conduit communicating with the discharge side of the gears and with the sump for conveying oil back to the sump, the casing having formed therein a by-pass comtrived to offer more frictional resistance to the flow of oil through it than the oil inlet con-- duit so as to create a back-pressure in the bypass in order to feed oil under pressure to the air-pumping impellers, and a valve 5. In a pumping device for oil burners, the combination of a sump, a pump casing having inlet and outlet passages formed therein, pumping means in the'casing for maintaining a constant level of oil in the sump, pair of air-pumping impellers also in the casing, an air inlet conduit communicating with the inlet side of the impellers and with the upper part of the sump for conducting air from -the sump to the impellers, a pair' of oil feed-pump gears in the casing, an oil inlet conduit communicating with the lower part of the sump and with the suction side of the gears for conveying oil uniformly to the gears, an oil outlet conduit communicating with the sump and with the discharge side of the gears for conveying. oil back to the sump, the casing having formed therein a by-pass communicating with the discharge side of the gears and with the suctionside of the impellers, the oil inlet conduit being oflarger cross-section area than the oil outlet conduit so as to impose a back pressure in the by-pass in order to feed oil to the airpumping impellers, and a fuel conduit oommunicating with the discharge side of the impellers for conveying air and oil mixture from the impellers.

FRANK FISCHER. GUDMUND SIVERTSEN.

municating with the discharge side of the gears and with the suction side of the impellers, the oil outlet conduit being contrived to offer more frictional resistance to the flow of oil through it than the oil inlet conduit so as to create a back-pressure in the by-pass in order to feed oil under pressure to the air-pumping impellers.

4. In a pumping device for oil-burners, the combination of a sump, means for maintaining a constant level of oil in the sump,

a um casin airum in im ellers in thecasing, separate air inlet and outlet conduits communicating respectively with the suction anddischarge sides of the impellers, a pair 7 of oil feed-pump gears in the casing, an oil inlet conduit communicating with the suction side of the feed-pump gears and with the lower part of the sump for supplying oil under a uniform suction head to the gears, an oil outlet conduit communicating with the discharge side of the gears and with the sump for conveying oil back to the sump, the casing having formed therein a by-pass communicating with the discharge side of the gears and with the suction side of the impellers, the oil outlet conduit being con-,

in the by-pass for controlling the amount 7 of oil fed to the impellers. 

